In a Patent Document 1, a multi-energy CT which radiates two kinds of X-rays which have different energy spectra is disclosed. When X-rays with a spectral band width transmit an object to be examined, since many X-rays in low energy are absorbed, a so-called beam hardening effect that an energy peak value shifts to a high side arises. It is known that the beam hardening effect causes artifact generation and accuracy deterioration of a CT value. In the multi-energy CT, it is considered that it is possible to reduce the artifact resulting from the beam hardening because good beam hardening compensation becomes possible using data acquired with two kinds of energy spectra, and hence, precision improvement of a CT value is expected.
In addition, in the multi-energy CT, it is considered that generation of an image which expresses an atomic number and a density is possible because it is possible to obtain data which expresses different attenuations from a Compton effect and a photoelectric effect, applications such as separation of a bone and a contrasted blood vessel, which is difficult in CT of a type which radiates one kind of energy spectrum, are expected.
Patent Document 1: Japanese Patent Application Laid-Open No. 2004-188187